Last year, while playing on a Toronto Raptors team that was very bad defensively, Chris Bosh posted a Defensive Rating of 104.7. Where Bosh really struggled was in the post, and this showed in the numbers. According to Synergy Sports Technology, Bosh ranked 114th in points per possession (PPP) allowed, giving up .84 PPP on 43.6 percent shooting. Bosh's struggles in the post were largely due to his pairing with Raptors center Andrea Bargnani, whose own shortcomings on the defensive end forced Bosh to defend centers on most nights. He simply couldn't handle them.

Bosh's move to Miami has turned him into a much better defender. So far this season, Bosh has posted a Defensive Rating of 103.3, which is well below the league average of 104.9. Bosh's biggest improvement seems to have been with his post defense, where Bosh is ranked 25th in the NBA in PPP allowed, only giving up .72 PPP on 38.1 percent shooting.

Bosh really benefits from the fact that he is now playing the power forward position at both ends of the court, meaning he is allowed to use his 6'11" frame to bother shots in the post.

Here, Golden State's David Lee makes the catch on the block and then makes a quick, strong move, actually getting a step on Bosh. However, Bosh recovers and gets his hands straight in the air. Lee forces up a tough shot from under the rim, and he ends up missing it.

Again here, Bosh's man (this time New Orleans' David West) gets himself in position to score from the block. Bosh's length is in West's head however, and West decides to try a reverse using the rim as a defender. This throws everything off, and West misses the shot.

In this clip, Wilson Chandler of the Knicks tries to post up Bosh. Bosh holds his ground as Chandler makes the catch, forcing Chandler to try and face up. However, Bosh's length is there again as he effectively contests the shot and forces the miss.

In addition to bothering shots, Bosh is now able to use his newfound length advantage to force the man posting him up into turnovers. According to Synergy, 14.5 percent of the time teams try to post up Bosh, the end result is a turnover:

In this clip, New York's Amar'e Stoudemire gets around Bosh, and looks as if he is going to take it to the rim for the easy finish. Again, Bosh is able to use his length to knock the ball away from Stoudemire without fouling, forcing the turnover.

Again, Bosh gets beat by an initial spin move and again, Bosh is able to use his length to make up for it. Here, Charlotte's Boris Diaw executes a great spin move, but he finds himself at the rim with no ability to actually go up for the shot because Bosh has his hand up, bothering the shot. Diaw gets himself caught in the air and ends up throwing the basketball away.

The biggest reason for Bosh's improvement in the post is that Bosh is now able to play better defense before his man makes the catch. What I mean by this is now that Bosh is defending fours, he is equal in terms of strength, and this allows him to push his man up off the block and away from his comfort zone:

After the Kings' Carl Landry sets a pindown screen for his teammate, you can see that he wants to post up right on the block. He is unable to because Bosh does a great job of leaning his body on Landry and forces Landry to post farther out than he would like. Another thing that Bosh does well is that he gets one hand out in the passing lane, forcing a bounce pass to the outside. These passes are slower, and they force the offensive player in the post to come meet the basketball, bringing the offensive player farther away from the post. That is what happens here, and after making the catch, Landry is forced to settle for a jumper that he misses.

This time, Charlotte's Tyrus Thomas tries to post up Bosh in transition, but Bosh is able to push him out of his comfort zone. Because Thomas is farther out than he would like, he is forced to turn and face and try to make a move to the basket. Thomas ends up taking more dribbles than he is comfortable with, and the result is a missed shot.

This is the biggest example of the difference between last year and this year. Last year, the opposing team's center would be posting Bosh up, and Bosh would be unable to get that same push. Now, against guys like Thomas, Bosh is able to throw his weight around a little bit more.

Despite all the improvement made by Bosh in the post, there are a few holes in his post defense. Maybe the biggest one takes place after Bosh's man makes the catch in the post. Once that happens, Bosh can be backed down rather easily. The key is that the post player mush be patient. We saw a perfect example of this during the Heat's game against the Blazers Sunday night:

Again, here Bosh does a fantastic job of using his body to force LaMarcus Aldridge way out from where Aldridge normally likes to post. However, instead of facing up and either settling for a jumper or making a dribble drive move (like we saw in the previous two clips), Aldridge stays patient, keeps his back to Bosh, and backs him down. Aldridge is able to get himself into the block, where he likes to operate, and he knocks down the shot.

Here is another example of Bosh fighting before the basketball gets passed to his man in the post, and he does a terrific job of doing so. Again though, when Aldridge makes the catch, he takes a deep breath and starts to back Bosh down. Bosh can't keep Aldridge from backing him down, and that forces him to attempt to try and "pull the chair," or step away in the hopes that the man backing him down travels or falls down.

Pulling the chair is a crafty move, but you don't want to be doing that in the fourth quarter. To me that shows weakness or an inability to stop your man from backing you down.

Bosh just seems to transform when his man goes from posting up without the ball to actually having the basketball. Maybe it is mental, maybe it is because he can get away with more pushing when his man doesn't have the basketball, but Bosh really struggles when his man commits to backing him down.

Bosh has been fighting perceptions that he is playing poor defense this year, in addition to being called weak and soft. As far as the defense is concerned, those who claim that Bosh is playing bad defense are way off base. Bosh's length advantage against the power forwards he is now defending allows him to bother shots, force turnovers, and keep post players from getting to their spot.

However, if a post player is patient and they stay determined to back Bosh down, they are going to be able to do so. I won't be surprised if we start to see teams letting their power forwards try to back Bosh down in the hopes of getting a bucket or forcing a double team.